Two cycle gas engine



Aug. 4, 1931. w w -r' 1,817,510.

TWO-CYCLE GAS ENGINE Original Filed Nov. 3, 1927 2 Sheets-Sheet 1 mm'amgpmr ATTOPNFV Aug. 4, 1931. w E. EWART 1,817,510

TWO-CYCLE GAS ENGiNE Original Filed Nov. 3, 1927 2 Sheets-Sheet 2 In? Z ATTORNEY 2;; exhaust ports arranged to Patented Aug. 4,1931 1 UNITED STATES WILLIAM E. EWART, OF SEATTLE, WASHINGTON 'rwo CYCLE GAS ENGINE Application filed November 3, 1927, Serial No. 230,735.

The invention is an internal combustion engine having two combustion chambers in a stationary cylinder, one combustion chamber being between the head of the cylinder 1 and the end of a movable hollow piston forming a movable cylinder, and another combustion chamber in the movable cylinder and between the head thereof and a movable piston therein; and an enlarged skirt dem pending'from the end of the movable cylinder forming a piston in a larger or scavenger cylinder; and a crankshaft having three throws or cranks, the center of the two outside cranks which are connected to the movable cylinder being in line and the center of the third or center crank which is connected to the movable piston in the movable cylinder is offset approximately 150 degrees from the center of the two outside cranks.

v The invention is an improvement over my prior Patent, No. 1,563,733 which was issued December 1st, 1925 in that the crankshaft connections are offset, the intake and regulate the fiow of the gases with the connecting rods in the offset position, and auxiliary tanks and connections shown between the scavenger cylinder and the intake or exhaust ports.

The object of the invention is to obtain the maximum amount of power with the minimum amount of weight and space.

Another object of the invention is to provide a combination cylinder having two combustion chambers with a movable hollow piston and an inner movable piston, with the pistons connected to opposite sides of a crankshaft in which the throws to the crankshaft are offset so that they are not directly opposite.

Another object of the invention is to provide a combination internal combustion enme having a movable cylinder forming, a

movable piston within a cylinder in whichv the ports are arranged to permit intake and exhaust to both cylinders.

Another object ofthe invention is to provide a two cycle internal combustion engine havin two explosion chambers with m n o f r b y f ed ng saai toth cyL also Renewed October 6, 1930.

inders or forcibly drawing the burnt gases out of the cylinders. I

A further object of the invention is to provide a combination cylinder for internal combustion engines having a movable cylinder forming a piston within a cylinder and also a movable piston in the movable cylinder in which there are two explosion chambers which explode alternately.

And a still further object of the invention is to provide suitable intake and exhaust ports in the walls of a combination internal combustion engine to permit compression and explosion in two individual chambers.

With these ends in view the invention embodies an internal combustion engine cylinder having a movable inner cylinder forming a piston with an inner movable piston within the said movable cylinder and in which the inner movable piston and movable cylinderare eccentrically connected to opposite sides of a crankshaft and the intake and exhaust ports arranged to permit the passage of the gases at the proper periods. The cylinder is also provided with an enlarged cylinder forming a scavenger cylinder which is connected to a tank through suitable valves to cause a vacuum in the tank and the tank is connected to the exhaust ports of the cylinders so that it will instantly draw the burnt gases out and a fresh charge in. The connections of this tank may be reversed so that compression will be created in the tank to blow the burnt v gases out and the fresh charge in. Jets may be provided inthe cylinders through which the fresh charge may be blown into the cylinders under pressure.

Other features'and advantages of the invention will appear from the following description, taken in connection with the drawings, wherein I Figure 1 is a vertical section through the center of the cylinder showing the inner movable piston and movable cylinder in the position in which the explosion occurs, and the outer cylinder and piston in the recharging and exhausting, position;

Figure-Zia a similarsection with thepo- 45 which a sitions of the pistons and cylinders reversed. Figure 3 is a side view of the combined movable cylinder and movable piston show ing the positions of the connecting rods with the movable cylinder in the position shown in Figure 1.

Figure 4 is a view showing the positions of the connecting rods at which point both the movable cylinder and inner movable piston begin to travel in the same direction while recharging and exhausting.

Figure 5 is a similar view with the pistons at the end of the compression stroke and in the position in which the explosion in the upper or outer cylinder is about to take place.

Figure 6 is a cross section showing part of the cylinder with a vacuum tank connected to the exl'aust ports of the cylinders "and to the scavenger cylinder.

Figure 7 is a similar view showing the tank on the OpPOSlIO side of 'the cylinder and connected to the intake ports and arranged so that air will 3 compressed in the tank. v

Fi -ure S-isa section similar to that shown in Figure in which injectors are shown to inject fuel into the cylinders.

Figure 9'is 'a 'si. iilar section on a different plane to tnat of Figure 3 showing the position of the pint-1.1 reversed as shown in "Figure 1.

In the drawings the cylinder is shown as it would be made wherein numeral '1 indicates the large or outer cylinder, nun'ieral 2 the scavenger cyln "r, numeral 3 the in a able cylinder forming he movable piston and numeral 4 the inner movable piston. 40 ife cylinder l'may be made in an'indivi al motor in a cylinder block or in combination with as many other cylinders as may be desired. In the design shown it is'provide the head 5 in-thec'ent'er of p a'rlr plagli maybe placed and in the walls the o '7 and Sfornisir dc ed. he

rigi'" spark plug t l co-ope ire with the in the piston 2 as )w'n in Figure 1 to lode tli; gas-es in "the l end of the c *rged portion in l 1 tscavcngcr c linder 2 is formed. This cylinder is fnovidcdwith a portlO which may be connected to a reservoir ll'wh-ich may be of my "itable e ai'id'the reservoir may be onnec r [to the ir alteports as shownin Figure 7 so that c pressed air and fuel from the reservoir may be'admitted to the X'plosion chambers ofthe cylinders and the burnt gases forced out by the incoming charge.

The piston of the scavenger cylinder 2 is formed by a skirt or outstanding flange 12 at the lower end of the piston 3 and the connecting rods 13 and 14 of the piston 3 are mounted on wrist pins 15 in hubs 16 in the shirt The opposite ends of the rods 13 and 14 are connected to a crankshaft 17 through hubs 18 as shown.

The piston 3 is made as shown with a chan'lber 19 in the head and an exterior opening 20 through which fuel is admitted from the port 7 as shown in Figure 2 and also through which tne is ignited by the spark plug 9 as shown in Figure 1. Below the chamber is a cylinder 21 in which the inner movable piston 4 is slidably inounte l. The walls of the cylinder 21 extending downward from the head of the piston may be provided with waterjackets shown and at the lower end is the flange 12 which forms thpiston of the cylinder The piston 3 is provided with an u per of piston rings as indicated by the numeral 22 and also a lower set 23 which are below the opening 20 so that the piston is sealed on both sides of the intal e port. The piston may also be made as show; and attached to the crankshaft 17 at a point approximately 150 degrees from the point at which the rods 13 and '14 of the movable cylinder are connected, through a connecting rod 21 having a hub 25 at the lower end. The wall of the movable cylinder 21 is provided with exhaust openings which co-opcrate with a circular recess 27 in the wall of the cylinder 1 to permit gases of the inner movable cylinder to exhaust'when the cylinder is in the position shown in FigureQ. The recess 27 is provided with an outlet opening 28 which may be connected to an exhaust header or any other suitable crevice. The piston 3 is provided with a bafile 29 against which the incoming through the port 7 will strike and be deflected upward asindicate'd by the arrows in Figure 1..

In the design shown in Figure 6 the port 10 of the cylinder 2 is shown as opening into a chamber 30'which may be made integral with the'cylinder or bolted to it as shown with the exhaust port 28 opening into it through an opening 31 and the exhaust port 8 opening into it through an opening 32. The port 10 opens into a chamber 33 be tween valves 3 1 and 35 and below the valve 35 is an outlet chamber 36 as shown. The stem '37- of the valve 35 is enlarged as shown and provided with a circular opening 38 through which the stem 39 of the valve '34 passes. The stem 39 is provided with a shoulder 40 which engages theupper end of the valve 35'to force it open as shown. The'lower en'd'of the valve stem 39 isheld in a sleeve 41 by nuts 42 and the lower end of the sleeve is provided with a roller 43 that engages a cam 44 on a cam shaft 45 which is rotated by gears 46, 47 and 48 from the crankshaft 17. The sleeve 41 is resiliently held downward by a spring 49 and the valve stem 37 of the valve 35 is resiliently held upward by a spring 50which is somewhat smaller than the spring 49. It will be observed that as the piston formed by the skirt 12 moves upward from the position shown in Figure 6 it will force gases in the cylinder 2 out through the valve 35 and as the piston reaches the top of the stroke the cam/44 will close the valve 35 and open the valve 34 so that as the piston moves downward it will draw air or gases from the chamber 30 and as it continues to operate it will create a vacuum therein. The cylinder 2 may be of such a size that it will have a greater displacement than the area of the two cylinders so that a partial vacuum will be maintained in the chamber 39 continuously.

In the design shown in Figure 7 the chamber 30 is positioned on the intake side of the cylinder with the opening 32 connected to the intake port 7 and the opening 31 omitted. In this design the opening 36 may be connected to a carburetor or any suitable gasoline supply and with the action of the valves reversed the cylinder 2 will maintain compression in the chamber 30. The vapor in the chamber 30 will therefore be under pressure so that it will instantly force the burnt gases out of the exhaust ports at the opposite sides and fill the cylinders with a fresh charge.

It is understood that although the cam shaft 45 is shown as being rotated by gears it may be rotated from the crankshaft by any other suitable means.

In the design shown in Figures 8 and9' the inlet port 7 is omitted and injectors 51 and 52 inserted in the sides of the cylinder and it will be observed that as the exhaust ports are closed by "he positions of the pitons the injectors will force fuel under pressure into the cylinders to instantly fill them. These sections are taken on different planes so that the injectors will not be inthe same plane and therefore will not correspond with the intake ports and therefore the injector of one cylinder will not correspond with the intake port of the other cylinder. The in jectors may be connected to a compressor as indicated by the numeral 53 which may be operated by any suitable means and located at any suitable position. The connection 54 between the compressor 53 and the injector may be provided with valve 55 in which operated by another cam 44 on the cam shaft 45. It is also understood that any other suitable 'force the piston 4 downward and the der 21 upward so that the piston 4 will ex- 7 means may be used for injecting or forcing a fresh charge into the cylinders.

It will be understood that changes may be made in the construction without departing from the spirit of the invention. One of which changes may be which the connecting rod of the inner movable cylinder is connected to the crankshaft in relation to the connecting rod of the inner movable piston. Another may be in the design of the inner or outer movable pistons, another maybe in the use of other means for controlling the intake and exhaust and still another may be in the use of other means for connecting the pistons to the crankshaft.

The construction will be readily understood from the foregoing description. In use the device may be assembled asshown with the inner movable cylinder forming a piston within the outer cylinder and with a combustion chamber between the end of the movable cylinder and inner end of the outer and an inner movable piston with in the movable cylinder forming another combustion chamber between the end of the inner piston and the inner end of the movable piston, with both the inner movable piston and movable cylinder connected to a common crankshaft at opposite sides thereof and with the throw of the inner movable piston approximately 150 degrees from the throw of the movable cylinder so that they are not directly opposed;

cylinder,

may be admitted or forced into the two cylinders, and the exhaust permitted to escape, blown'out by the incoming charge, or drawn out by a vacuum; or all of the various arrangements may be used in combination with the vacuum chamber drawing out the burnt gases, the compression chamber forcing air into the cylinder to thoroughly cleanse it, and an injector forcing the fresh charge in after the intake and exhaust ports have been closed by movement of the piston and cylinder; in which instance the vacuum may be created by the scavenger cylinder of one cylinder of engine, the compression by the scavengercylinder of another cylinder, and the injection by an auxiliary compressor, or either the vacuum or compression formed by an auxiliary pump or compressor. Vhcn it is in the position shown in Figure 1 air will be admitted through the intake port and exhausted through the exhaust port of the upper or larger cylinder and after all gases are exhausted a fresh charge may be injected, while at the same time the fuel will be compressed in the inner movable cylinder 21 and as it arrives at the position shown this fuel will. be ignited and as it explodes it will cylinert a downward pressure on one side of the in the exact angle at and the cylinders provided with ports arranged so that fuel crankshaft while the cylinder 21 exerts an upward pressure on the opposite side and then as the piston and cylinder arrive at the positions shown in Figure 2, air will be admitted to the cylinder through the port 7 and when the exhaust gases are forced out through the exhaust port 28 a fresh charge will be injected, and at the same time as it arrives at this position the spark plug 6 will ignite the in the cylinder 1 and as they explode they will force the piston 3 down- Ward which will exert a downward pressure 011 the crankshaft. It is understood that any of the various means for injecting a fresh charge of fuel or exhausting the burnt gases may be used in combination with the engine cylinder having an inner movable piston with an opening forming a cylinder therein and an inner movable piston in the said movable cylinder, the most preferred arrangement being a combination of the designs shown in Figures 7, 8 and 9 in which the compression ofthe scavenger cylinder forces the burnt gases out and as soon as the cylinder is clean and the pistons have moved so that the exhaust and intake ports are closed the injector, whichis connected to the auxiliary compressor, injects the fresh charge of fuel into the cylinder. This assures a clean cylinder after each explosion. The vacuum chamber shown in Figure -6 may also be combined with the jets shown in Figures 8 and 9 so that the burnt gases will. be drawn out by the vacuum and then as soon as the pistons have moved to close the ports, a fresh charge of fuel injected into the cylinders.

It will be observed that with the relative positions of the connections of the connecting rods to the crankshaft, wherein the connection of the connecting rods of the movable cylinder is offset slightly, the maximum amount of efliciency will be obtained as the pull of the rods 14- is not directly opposed to the downward force of the rod 24. The

greatest force is applied as the explosion occurs and with this connection in the position shown in Figure 3 the upward pull will be instantly exerted on the crankshaft with the best possible leverage. This arrangement also aids in the exhaust as it permits both the movable cylinder and the movable piston to travel in the same direction for a short distance at the end of the exhaust stroke or when the points are moving from the position shown in Figure 4 to that shown in Figure 5. In these views it will be observed that when the connecting rods 14 are at the upper end of their stroke the connecting rod 24 will be a short distance from the lower end of its stroke and as it moves the remainder of the distance, the connecting rods 14 also start on their downward move- 'ment so-that both are moving downward at the same time and while the exhausted.

The angle of offset in the drawings is shown as degrees however it will be observed that the connection may be offset to any suitable angle.

Having thus fully described the invention, what I claim as new and desire to secure by Letters Patent, is

1. in a two cycle internal combustion engine, a cylinder, a movable cylinder forming a piston with a combustion chamber within the said cylinder, an inner movable piston within the said movable cylinder with another combustion chamber formed between the end of the inner piston and the movable gases are being cylinder head, suitable connections betweenthe said piston and movable cylinder to a common crankshaft, with the connection of the inner piston approximately 150 degrees from that of the movable cylinder so that the pistons are not opposed, an enlarged cylinder, an enlarged piston depending from the said movable cylinder, an auxiliary chamber connected to the said intake ports and means for connecting the said auxiliary chamber to the said enlarged cylinder, said cylinders having a common intake port for both inner and outer cylinders and exhaust ports, and said movable cylinder having one intake and one exhaust port both corresponding with the intake and exhaust ports of the outer cylinder, and means connecting the said ports to the said enlarged cylinder.

2. In a two cycle internal combustion engine, a movable piston within a movable sleeve piston, an outer cylinder, an enlarged cylinder, an enlarged piston depending from the said sleeve piston connections between the said pistons to a common crank shaft with the connection of the inner piston approximately 150 degrees from that of the movable cylinder so that the pistons are not opposed, intake ports to said outer cylinder and to said sleeve piston, intake ports in said sleeve piston, exhaust ports in said cylinder and sleeve piston, the said intake and exhaust ports of the said inner and outer cylinders corresponding, and the said intake and exhaust ports of the said movable cylinder corresponding with the intake and exhaust ports of the said outer cylinder. an explosive chamber within the outer cylinder, another explosive chamber within the said sleeve piston and above'said inner movable piston, an auxiliary chamber connected to the said exhaust ports and means for connecting the said auxiliary chamber to the said enlarged cylinder, and means connecting the said ports to the said enlarged cylinder.

3. In a device of the class described, a cylinder, a movable cylinder forming a movable piston within the said former cylinder, an inner movable piston within the said the movable cylinder,

movable cylinder, a skirt depending from the lower end of the said movable cylinder forming a larger piston in another cylinder formed in an enlarged portion at the lower end of the said former cylinder, suitable means for connecting the said movable cylinder and inner piston to a common crankshaft, with the inner piston connection approximately degrees ahead of that of said outer cylinder having a common intake port for both inner and outer cylinders and two exhaust ports, and said movable cylinder having one intake and one exhaust port both corresponding with the intake and exhaust ports of the outer cylinder. at. In a device of the class described, a cylinder, a movable cylinder forming a movable piston within the said former cylinder with a combustion chamber between the cylinder head and end of the piston, and inner movable piston within the said movable cylinder with another combustion chamber between the inside of the end of the said movable cylinder and end of the inner piston, a skirt around the lower end of the said movable cylinder forming another piston in another cylinder formed in an enlarged portion in the lower end of the said former cylinder, said cylinder having a common intake port for both inner and outer cylinders and exhaust ports, and said movable cylinder having one intake and one exhaust port both corresponding with the intake and exhaust ports of the outer cylinder. 5. In a device of the class described, a cylinder, a movable cylinder forming a movable piston within the said former cylinder, an inner movable piston within the said movable cylinder, said pistons and cylinders forming two explosion chambers, said stationary cylinder having a common intake port for both cylinders and two exhaust ports, and said movable cylinder having one intake and one exhaust port, both corresponding with the ports of the stationary cylinder, a skirt around the lower end of the said movable cylinder forming another piston in another cylinder formed in an enlarged portion in the lower end of the said former cylinder, suitable means for connecting the said pistons to a common crankshaft with the inner piston connection to the crankshaft approximately 150 degrees from that of the said movable cylinder, suitable intake and exhaust ports, and means for igniting the gases in the said cylinder.

WILLIAM E. EWART. 

